Picture this.

You're Liam Hemsworth. You're engaged to Miley Cyrus. You've been drinking all night and are thus hammered. You think someone throws a rock at you. What do you do?

Punch him in the face. Derp.

The Dec. 9 fight in Philadelphia, where Liam is filming the aptly-named 'Paranoia,' started after he left a bar in the wee hours and accused another bar patron (supposedly named Rob) of literally casting stones.

This led to a brawl, with reports indicating that while Rob clung to Liam's legs, the Aussie 'Hunger Games' actor pummeled him in the face. So that sounds awkward.

Police later arrived to disperse the crowd of lookyloos. No one was arrested, but Rob supposedly blustered, “I don’t think [Liam] fared much better.” Which were mighty big words from a guy who was lying on the ground eating a late-night snack of pavement.

Way to be, Rob.

This isn't the first time Liam has let loose with the fists -- back in 2009, a security guard had to get involved to stop a fight he and his brother Chris Hemsworth (you may know him better as Thor in 'The Avengers') had with someone outside a Hollywood nightclub.

And here we thought Australians were a peaceful people.